The present disclosure relates to a cable storage device for an electrical charging cable of a rechargeable battery of a hybrid or battery-operated electric vehicle, and also to a hybrid or battery-operated electric vehicle, in particular an electric car, having a cable storage device of this kind.
An electric vehicle and also a cable storage device for an electrical charging cable of a rechargeable battery of a hybrid or battery-operated electric vehicle, in particular of an electric car, of the kind cited in the introductory part are known, for example, from WO 2012/031617 A1. A rotatable drum, onto the circumferential surface of which the charging cable can be wound, has, on the circumferential surface, a groove-like guide profile which runs in the form of a helix and which receives the charging cable. The drum is accommodated in a protective pipe. The protective pipe has a longitudinal slot through which the charging cable is passed. A sleeve part which surrounds the protective pipe and can be displaced along the drum and has a passage opening for the charging cable is provided for improved guidance of the charging cable during winding and unwinding. A slotted-link control device, such as a nut, is provided for axially displacing the sleeve part relative to the drum. The slotted-link control device can be screwed onto the guide profile of the drum to displace the sleeve part over a slotted-link block which is guided through the longitudinal slot in the protective pipe when the drum rotates.
Furthermore, DE 10 2009 046 327 A1 discloses an apparatus for electrically connecting an electric vehicle to a power tap point which likewise provides a cable drum which is mounted such that it can rotate on a stationary vehicle structure. In order to guide the charging cable in an ordered manner when winding the charging cable onto or unwinding the charging cable from the drum, the apparatus has an oscillator which receives the charging cable in a passage opening and is mounted such that it can move in the direction of the drum axis on a guide shaft which is driven in rotation. The oscillator can additionally be forcibly guided on the guide shaft by a slotted-link control device.
DE 10 2010 061 892 A1 discloses a charging device for an electric vehicle having a charging cable and a rotatably mounted cable drum. The charging cable is wound onto the cable drum in a two-dimensional manner for the purpose of winding the charging cable onto and unwinding the charging cable from the cable drum in an ordered manner. The drum has two lateral boundaries for the wound-on charging cable, with the distance between the two lateral boundaries being smaller than twice the diameter of the charging cable.
U.S. Pat. No. 5,299,670 discloses a telephone cable retractor which comprises a cylindrical, hollow cable drum with a helically running channel which is made on the circumferential surface of the cable drum and in which the telephone cable can be received. The retractor further comprises a cable guide which is guided on a rail. The cable guide has a projection which interacts with the helical channel in the cable drum in such a way that the cable guide is moved on the rail in the axial direction of the cable drum when the cable drum rotates, in order to thereby insert the telephone cable into the helical channel in an ordered manner. The retractor has a rotary spring, which is fitted within the hollow cable drum, for winding the telephone cable onto the cable drum.
Against this background, one object of the present disclosure is to provide a cable storage device for an electrical charging cable of a rechargeable battery of a hybrid or battery-operated electric vehicle which provides an alternative to the known prior art, and also a hybrid or battery-operated electric vehicle, in particular an electric car, having a cable storage device of this kind, which allows the charging cable to be wound onto and unwound from a cable drum in a simple and convenient manner, in particular in an ordered manner, with the cable and the cable storage device having a relatively long service life.
This object is achieved by a cable storage device having the features described by claim 1. The object is further achieved by an electric vehicle having the features of claim 11 as well as the method described by claim 16. Further, particularly advantageous refinements of the disclosure are disclosed in the respective dependent claims.
It should be noted that the features listed individually in the claims can be combined with one another in any desired, technically reasonable manner and form further refinements of the disclosure. The description additionally characterizes and specifies the disclosure, in particular in connection with the figures.
According to one non-limiting embodiment, a cable storage device for an electrical charging cable of a rechargeable battery of a hybrid or battery-operated electric vehicle, such as an electric car, has a rotatable drum onto the circumferential surface of which the charging cable can be wound. Furthermore, the drum is mounted in a rotatable manner on a rotationally fixed shaft, with the shaft having an external thread, and the drum having an internal thread which engages the external thread. In other words, rotary movement of the drum therefore likewise leads to an axial displacement movement of the drum in relation to the shaft. In this way, a movable cable guide for winding the charging cable onto or unwinding the charging cable from the drum in an ordered manner, as is known from the prior art mentioned in the introductory part for example, can be dispensed with, as a result of which the design of the cable storage device is simplified. Winding the charging cable onto or unwinding the charging cable from the drum in an ordered manner can be realized solely by the axial displacement movement of the drum in relation to the stationary shaft.
According to another embodiment of the disclosure, the drum has axial ends at each of which a drum end disk is arranged. The diameter of the drum end disk is greater than the diameter of the drum. The drum end disks define the axial section of the drum in which the charging cable can be wound on (wind-on section), and therefore prevent the charging cable from being wound on outside this section.
A further embodiment of the disclosure makes provision for the drum end disks to be mounted in an axially displaceable and rotationally fixed manner in relation to the shaft, with the drum end disks being rotatably connected to the respective axial ends of the drum. Therefore, the entire axial wind-on section of the drum, which section is defined by the drum end disks, is displaced in the axial direction of the shaft when the charging cable is wound on or unwound, but with the drum end disks not rotating relative to the shaft during the axial displacement movement of the drum. The arrangement of the drum end disks in a rotationally fixed manner in relation to the shaft allows the drum end disks to be provided with functions other than that of defining the wind-on section.
Therefore, in another embodiment, at least one tension spring element is provided, the direction of the action of force of the tension spring element running substantially parallel to the axis of the shaft and the tension spring element acting on an end face of the drum end disk. In particular, the tension spring element preferably acts on the end face of the drum end disk in such a way that the tension spring element is pulled and stretched when the charging cable is unwound from the drum and therefore during the corresponding axial displacement movement of the drum end disks away from one another. The process of winding the charging cable onto the drum is assisted in this way since the tension spring element pulls the drum in the direction of the axial displacement direction of the drum which corresponds to the winding-on operation.
According to yet another embodiment, the drum end disks each have a recess which extends radially inward from their circumferential surfaces and into which a second, stationary shaft which runs parallel to the axis of the shaft and causes the drum end disks to be mounted in a rotationally fixed manner in relation to the shaft engages.
In order to assist the process of winding the charging cable onto and unwinding the charging cable from the drum in an ordered manner, a groove-like guide profile for receiving the charging cable is formed on the circumferential surface of the drum according to a yet another embodiment. In such an embodiment, the guide profile runs in a helical manner around the outside of the drum.
According to another embodiment, the radial depth of the recess is such that the shortest distance between the circumferential surface of the second shaft and the circumferential surface of the charging cable which is received in the guide profile is smaller than the diameter of the charging cable. This prevents the charging cable which is wound onto the drum from being able to slip, for example, out of one guide groove into an adjacent guide groove.
A further embodiment of the disclosure makes provision for the drum to be arranged in a housing which surrounds the charging cable in the state in which the charging cable is wound onto the drum, with the housing having a passage opening for pulling out the cable. The charging cable is therefore protected against soiling. Rotatable rollers can be provided at the passage opening in the housing, the rotatable rollers allowing the charging cable to be easily pulled out of the housing and, in the process, likewise preventing damage to the charging cable, for example by the edges of the passage opening. Furthermore, brush or wiper elements can likewise be provided in the edge region of the passage opening, the brush or wiper elements serving to remove particles of dirt from the charging cable.
A further embodiment of the disclosure provides a switching mechanism which establishes an electrical connection between the charging cable and the rechargeable battery as soon as the charging cable is completely unwound from the drum and otherwise disconnects the electrical connection. This prevents a portion of the charging cable which is still wound onto the drum from forming an electrical coil during the charging process. A switching mechanism of this kind can be realized, for example, by one of the two drum end disks by the one of the two drum end disks establishing the electrical contact between the charging cable and the rechargeable battery which is to be charged when it reaches its axial end position in which the entire charging cable is unwound from the drum.
A hybrid or battery-operated electric vehicle according to the disclosure, in particular an electric car, is characterized by the presence of a cable storage device such as described in this disclosure.
The embodiments, examples and alternatives of the preceding paragraphs, the claims, or the following description and drawings, including any of their various aspects or respective individual features, may be taken independently or in any combination. Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.
The various features and advantages of this disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows.